Archive | February, 2017

When Small Problems Become Big Issues

When a 58’ Kady Krogen trawler recently hauled out at Lauderdale Marine Center, our running gear company, High Seas Yacht Service was hired to pull the props and shafts for a routine cutlass bearing and seal service. High Seas Hydraulics was also hired to do routine service on the ABT Trac hydraulic stabilizer systems.

Damaged threads on shaft

Once we dropped the stabilizer fin in order to replace the lower shaft seals, we found the threaded stud on the bottom of one of the shafts was damaged and had signs of thread damage and galling.  This was most likely from a stainless steel nut on stainless steel threads that was installed and removed without the proper never seize.  This compromised the re-installation of the stabilizer fin nut so we recommended removing the shaft to repair it in our machine shop, Straight Line Marine. Once in the machine shop, we found that the stabilizer shaft was bent 0.080” which is significant for a stabilizer shaft. When we started the straightening process, which involves applying hydraulic force on the high point of the shaft the stabilizer cracked in two.  That was a first – never had that happen before.  Under examination of the broken ends it is evident that a crack in the shaft had worked its way to 20% through – we just finished off the job.

Cracked shaft

 

This particular vessel is under new ownership so there is limited history as it relates to past problems and repairs. Obviously, this stabilizer was badly damaged at some point in the past. In all likelihood, the boat probably hit something or experienced a hard grounding which lead to a crack in the stabilizer shaft. Over time, these cracks tend to creep and grow.

We were able to source a new stabilizer shaft from the manufacturer and complete the overhaul on the hydraulic stabilizer system.

We have never experienced a stabilizer shaft cracking in two before in our machine shop, but it just goes to show that a small thing such as damaged threads can be a warning sign of bigger issues.

Performing a Major Overhaul on NAIAD Stabilizer System

Continuing the work on the 135’ Broward, we have moved on to work on the NAIAD stabilizer system. While NAIAD does not specify an exact interval for performing a major overhaul, it does recommend replacing the lower seals every three years or 4,000 operating hours. Interim service and maintenance should be performed annually but a major overhaul is highly recommended anytime you find water in the grease beyond the outer shaft seals or signs of grease oozing from the inner seals around the shaft.  Once salt water compromises the grease the bearings will start to deteriorate and the grease needs to be replaced

For this project the customer wanted the major overhaul which encompasses removing the fins from the boat, removing the top plate, tiller arm, hoses and shaft. Taking apart the cylinders, inspecting the potentiometer. Basically, the entire system is removed and stripped down.

The upper and roller bearings are installed on the shaft. So when the shaft is removed the roller bearings stay with it. The roller bearings are cut off the shaft in our machine shop, Straight Line Marine. Next the shaft is polished in a lathe and inspected for corrosion or scarring in the lip seal area   . If we do find corrosion, we will clad the corroded area. In this case, we did find corrosion. Once the work on the shaft was complete, we installed new bearings using heat to avoid scoring the shaft.

Cladding shaft

Once the vessel is launched, we will bring up the electronic side of the system and test or reset the potentiometers. It is usually not until this late stage in the project that we can determine if the potentiometers need to be replaced. Once we completed all the steps for this major overhaul, we reassembled the unit and re-installed it back in the boat. The hydraulic stabilizer system on this Broward yacht is good as new and ready to take the captain and crew on more adventures and smooth sailing.

For more information on performing major overhauls on hydraulic stabilizer systems, check out our technical article on the process.

Manually Raising a Hydraulic Swim Platform After a Failure

 

Platform submerged

Our hydraulics team at High Seas Hydraulics was recently called out to help the captain of a 95 foot Technema yacht docked behind a private residence with a problem with the ship’s hydraulic swim platform. The hydraulic swim platform was stuck in the down position below the water line and leaking hydraulic fluids into the water. Before the team started to work on raising and securing the hydraulic swim platform, they needed to contain the leaking hydraulic fluids.  Upon arriving on site, they quickly deployed a special containment boom and secured it to the transom of the boat. They also used absorbent pads to filter the hydraulic fluids that had already leaked into the water. Once the boom was secured, the work could commence to start to raise the hydraulic swim platform so that the yacht could be moved to a yard for repair.

For this job, we hired professional divers to deploy air bags under the platform to raise it enough to use a pulley and ratchet system to hoist the hydraulic swim platform back onto the the locking hooks on the transom of the boat where it would normally rest. We first needed to

Divers with air bags

secure the hydraulic swim platform with straps that we could attach to the ratchet system in order to help raise it after the air bags
were inflated.

Once the hydraulic swim platform was raised a couple of inches with the air bags, we disconnected the hydraulic hoses on the inboard side of the unit to alleviate back pressure to help stem the flow of any additional hydraulic fluid into the water.  Relieving the back pressure also allowed the hydraulic cylinders to move more freely in order to raise the hydraulic swim platform. After the hydraulic swim platform was aligned and snug to the boat, it was further secured with straps and the locking hooks for its journey to the boat yard.

Platform secured to transom

One of the primary reasons for a failure of this type is wear and tear and prolonged exposure to sea water of the hydraulic cylinders and hoses that are located on the outboard side of the yacht. To avoid this type of problem, it is a good idea to inspect the hydraulic cylinders and hoses every time the boat is hauled and refurbish or replace them at the first sign of wear on the components. Spending a little time and money to keep the parts of the hydraulic swim platform that are exposed to sea water in top operating condition can ultimately save you big money in the future, not to mention potential fines and citations should your vessel leak hydraulic fluids into the waterways. While this type of failure is not prevalent, the day after we performed this job we were called out to perform the exact same thing on a 64 foot Azimut.

Refurbishing a Hydraulic Steering System on a 135 foot Broward Yacht

 

As part of the refit of the 135 foot Broward, the new owner wanted a complete overhaul done on the hydraulic steering system. We started by removing the steering cylinders for tear down and reseal before sending them out to be painted.

We next disassembled and removed the hydraulic power unit (HPU). The HPU consists mainly of a pair of motors, a reservoir tank and a hydraulic pump. These units can generate a tremendous amount of power to drive most any kind of hydraulic ram. Hydraulic Power Units are based on Pascal’s law of physics, drawing their power from ratios of area and pressure. In this case, the HPU takes the commands from the helm to push the hydraulic rods in the right direction to steer the yacht. A failure of the hydraulic steering system at sea or just about anywhere could prove to be catastrophic.

Once the unit was out of the boat, we cleaned the tank, check the values, sent the electronic motors out for testing and tested all of the pumps to ensure they were in good working order. We also made all new hoses for the unit in our hydraulics shop.

Once all parts were examined for quality control purposes, we reassemble the HPU and installed it back in the boat. A completely refurbished hydraulic steering system to like-new specifications will help to provide peace of mind that this yacht and her crew can safely navigate through any waters.

 

 

 

 

Whether you need hydraulic repairs, running gear work or shafts straightened – High Seas Family of Companies is here to serve

It’s not unusual for mega yachts to haul out at Lauderdale Marine Center requiring extensive work on multiple parts of the boat. That was the case for a 135 foot Broward yacht when she came into the yard. The Captain of the yacht approached High Seas with a laundry list of requirements that included hydraulics and running gear jobs. High Seas is unique in the sense that we have the expertise to work on both areas, providing a central point of contact that can help to design the most efficient work flow through coordinated schedules.

For this yacht, we were hired to:

  • Perform a full NAIAD 505 service with shafts out and new bearings
  • Do a full rebuild on the Hydraulic Steering System including removing the HPU and replacing hoses
  • Reinstall PTOs on new generators with new hoses
  • Refurbish the steering cylinders
  • Remove rudders for a bearing inspection and repack stuffing boxes
  • Remove shafts for new bearings, packing and alignment
  • Complete removal and rebuild of Maxwell 11000 windlasses

In coming posts, we will walk through the steps we took to make this yacht ship shape again.